Delayed signal propagation via CA2 in rat hippocampal slices revealed by optical recording.
Delayed signal propagation via CA2 in rat hippocampal slices revealed by optical recording.
复制标题
光学记录显示大鼠海马切片中 CA2 信号传播延迟。
DOI：
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发表时间：
1997
影响因子：
2.5
通讯作者：
Jin Murayama
中科院分区：
文献类型：
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作者：
Yuko Sekino;Kunihiko Obata;Manabu Tanifuji;Makoto Mizuno;Jin Murayama
在大鼠海马脑片上，用光电记录相结合的方法研究了苔藓纤维到CA 1区神经元的信号传递。通过斜切海马的中间部分来制备切片以保留纤维连接。刺激苔藓纤维，在CA 1区中部诱导群体锋电位（PS）和兴奋性突触后电位。最大PS在CA 1切片之间变化很大，他们的范围从7到13.5毫秒，有两个最大值在9和11.5毫秒。最快的PS可能是诱发的谢弗侧支连接的CA 3和CA 1地区在著名的三突触电路。然而，较慢的PS表明存在额外的延迟输入。为了确定延迟输入的来源，切片用电压敏感染料RH 482染色，并通过高分辨率光学成像系统检测与膜电位变化相关的光学信号。对苔藓纤维刺激的响应的光学记录表明从CA 3到CA 1的两种不同类型的信号传播。在制剂显示的快速类型的传播，信号传播到CA 1苔藓纤维刺激后的7.2毫秒内。在这种传播过程中，活动直接从CA 3流向CA 1的辐射层。其他制剂显示了缓慢的信号传播，其中光信号在传播到CA 1之前在CA 2中产生。在这种缓慢的信号传输过程中，活动持续在CA 2及其周围地区为3毫秒，然后传播到层辐射和oriens在CA 1。在这种情况下，CA 1活性检测苔藓纤维刺激的10.8毫秒内。在一些切片中，观察到快速和慢速传播模式的混合，表明这两种传输模式可以共存。我们的数据表明，CA 2神经元可以传递延迟兴奋信号给CA 1神经元。因此，我们的结论是，考虑通过海马体的电信号传播应包括通过CA 2区除了传统的齿状回CA 3-CA 1三突触电路的流量。
Signal propagation from mossy fibers to CA1 neurons was investigated in rat hippocampal slices by a combination of electrical and optical recordings. The slices were prepared by oblique sectioning of the middle part of the hippocampus to preserve fiber connections. The mossy fibers were stimulated to induce population spikes (PSs) and excitatory postsynaptic potentials in the middle part of the CA1 region. Latencies of maximal PSs in CA1 varied widely among slices; they ranged from 7 to 13.5 ms, with two maxima at 9 and 11.5 ms. The fastest PSs probably are evoked by the Schaffer collaterals that connect the CA3 and CA1 regions in the well-known trisynaptic circuit. However, the slower PSs suggest the existence of additional delayed inputs. To determine the source of the delayed input, slices were stained with a voltage-sensitive dye, RH482, and the optical signals relevant to membrane potential changes were detected by a high-resolution optical imaging system. Optical recording of responses to mossy fiber stimulation indicated two distinct types of signal propagation from CA3 to CA1. In preparations evincing the fast type of propagation, signals spread to CA1 within 7.2 ms after the mossy fiber stimulation. During such propagation, activity flowed directly from CA3 to the stratum radiatum of CA1. Other preparations illustrated slow signal propagation, in which optical signals were generated in CA2 before spreading to CA1. During such slow signal transmission, activity persisted in CA2 and its surrounding area for 3 ms before propagating to the strata radiatum and oriens in CA1. In such cases, CA1 activity was detected within 10.8 ms of mossy fiber stimulation. In some slices, a mixture of the fast and slow propagation patterns was observed, indicating that these two transmission modes can coexist. Our data reveal that CA2 neurons can transmit delayed excitatory signals to CA1 neurons. We therefore conclude that consideration of electrical signal propagation through the hippocampus should include flow through the CA2 region in addition to the traditional dentate gyrus-CA3-CA1 trisynaptic circuit.
影响因子：
56.9
作者：
ZOLAMORGAN, SM;SQUIRE, LR
通讯作者：
SQUIRE, LR